The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
L. Spainhower - One of the best experts on this subject based on the ideXlab platform.
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Commercial fault tolerance: a tale of two Systems
IEEE Transactions on Dependable and Secure Computing, 2004Co-Authors: W. Bartlett, L. SpainhowerAbstract:This paper compares and contrasts the design philosophies and implementations of two computer System families: the IBM S/360 and its evolution to the current zSeries line, and the Tandem (now HP) Nonstop/spl reg/ Server. Both Systems have a long history; the initial IBM S/360 machines were shipped in 1964, and the Tandem Nonstop System was first shipped in 1976. They were aimed at similar markets, what would today be called enterprise-class applications. The requirement for the original S/360 line was for very high availability; the requirement for the Nonstop platform was for single fault tolerance against unplanned outages. Since their initial shipments, availability expectations for both platforms have continued to rise and the System designers and developers have been challenged to keep up. There were and still are many similarities in the design philosophies of the two lines, including the use of redundant components and extensive error checking. The primary difference is that the S/360-zSeries focus has been on localized retry and restore to keep processors functioning as long as possible, while the Nonstop developers have based Systems on a loosely coupled multiprocessor design that supports a "fail-fast" philosophy implemented through a combination of hardware and software, with workload being actively taken over by another resource when one fails.
W. Bartlett - One of the best experts on this subject based on the ideXlab platform.
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Commercial fault tolerance: a tale of two Systems
IEEE Transactions on Dependable and Secure Computing, 2004Co-Authors: W. Bartlett, L. SpainhowerAbstract:This paper compares and contrasts the design philosophies and implementations of two computer System families: the IBM S/360 and its evolution to the current zSeries line, and the Tandem (now HP) Nonstop/spl reg/ Server. Both Systems have a long history; the initial IBM S/360 machines were shipped in 1964, and the Tandem Nonstop System was first shipped in 1976. They were aimed at similar markets, what would today be called enterprise-class applications. The requirement for the original S/360 line was for very high availability; the requirement for the Nonstop platform was for single fault tolerance against unplanned outages. Since their initial shipments, availability expectations for both platforms have continued to rise and the System designers and developers have been challenged to keep up. There were and still are many similarities in the design philosophies of the two lines, including the use of redundant components and extensive error checking. The primary difference is that the S/360-zSeries focus has been on localized retry and restore to keep processors functioning as long as possible, while the Nonstop developers have based Systems on a loosely coupled multiprocessor design that supports a "fail-fast" philosophy implemented through a combination of hardware and software, with workload being actively taken over by another resource when one fails.
Haruo Yokota - One of the best experts on this subject based on the ideXlab platform.
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A high-availability software update method for distributed storage Systems
Systems and Computers in Japan, 2006Co-Authors: Dai Kobayashi, Akitsugu Watanabe, Toshihiro Uehara, Haruo YokotaAbstract:SUMMARY In this paper, we propose a Nonstop System upgrademethod without significant performance degradation fordata management software. To reduce disk accesses andnetwork traffic, we construct logical nodes inside a physicalnode and migrate data between the symbiotic logical nodes.This logical migration is assisted by storage managementfunctions that hide data location and migration from users.We also show the effectiveness of our method using experi-mental results on the System based on the AutonomousDisks we have proposed as a highly available storage sys-tem technology. © 2006 Wiley Periodicals, Inc. Syst CompJpn, 37(10): 35–46, 2006; Published online in Wiley Inter-Science (www.interscience.wiley.com). DOI 10.1002/scj.20503 Key words: network storage; high availability;ceaseless update; storage management. 1. Introduction Recently, although the complexity of software tomanage data on storage Systems has increased becauseSystems have become larger, the software also requirescontinued high availability.Large-scale storage Systems are constructed from agreat number of magnetic hard disk drives (HDDs), ornodes, with consideration for both costs and performance.In such Systems, the software to manage data providesseveral functions: storage virtualization to provide a unifiedstorage image, data redundancy control to protect dataunder disk failure, and so on.It is crucial that software is updated with no servicedowntime. The software may require updating after distri-bution for many reasons, such as bug fixes and scope creep.However, to avoid great losses of productivity, serviceopportunities, and so on, Systems cannot be stopped.For the following discussion, we introduce two mod-els of relations between the location of the storage manage-ment and the data store:
S. Englert - One of the best experts on this subject based on the ideXlab platform.
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Compcon - Load balancing batch and interactive queries in a highly parallel environment
COMPCON Spring '91 Digest of Papers, 1991Co-Authors: S. EnglertAbstract:It is pointed out that resource-intensive batch query processing can adversely affect the performance of concurrently executing response time-critical interactive workloads such as online transaction processing. This is especially true in loosely coupled client-server multiprocessor architectures without centralized scheduling or load-balancing mechanisms such as the Tandem Nonstop System. In this environment, a low-priority batch query may be able to monopolize high-priority database servers in several processors in parallel at the expense of high-priority interactive work. This problem, known as priority inversion, requires special treatment if mixed (batch and interactive) workloads are to be viable. Relevant features of Tandem's Guardian 90 operating System are described. >
Dai Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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A high-availability software update method for distributed storage Systems
Systems and Computers in Japan, 2006Co-Authors: Dai Kobayashi, Akitsugu Watanabe, Toshihiro Uehara, Haruo YokotaAbstract:SUMMARY In this paper, we propose a Nonstop System upgrademethod without significant performance degradation fordata management software. To reduce disk accesses andnetwork traffic, we construct logical nodes inside a physicalnode and migrate data between the symbiotic logical nodes.This logical migration is assisted by storage managementfunctions that hide data location and migration from users.We also show the effectiveness of our method using experi-mental results on the System based on the AutonomousDisks we have proposed as a highly available storage sys-tem technology. © 2006 Wiley Periodicals, Inc. Syst CompJpn, 37(10): 35–46, 2006; Published online in Wiley Inter-Science (www.interscience.wiley.com). DOI 10.1002/scj.20503 Key words: network storage; high availability;ceaseless update; storage management. 1. Introduction Recently, although the complexity of software tomanage data on storage Systems has increased becauseSystems have become larger, the software also requirescontinued high availability.Large-scale storage Systems are constructed from agreat number of magnetic hard disk drives (HDDs), ornodes, with consideration for both costs and performance.In such Systems, the software to manage data providesseveral functions: storage virtualization to provide a unifiedstorage image, data redundancy control to protect dataunder disk failure, and so on.It is crucial that software is updated with no servicedowntime. The software may require updating after distri-bution for many reasons, such as bug fixes and scope creep.However, to avoid great losses of productivity, serviceopportunities, and so on, Systems cannot be stopped.For the following discussion, we introduce two mod-els of relations between the location of the storage manage-ment and the data store:
